Hello,
First, please understand that I am living/working in the Middle East. Supplies and medications are EXTREMELY LIMITED and I cannot obtain certain items here (like aquarium salt that is not mineral salt). Cannot order anything online bc we do not have a mailing address in the UAE. If you lived here, you would understand. Please bear this in mind when responding.

12 days ago I bought a betta from a crappy pet store and put him in a two gallon vase. Noticed immediately that he had ich. Next day went to a different store to buy the only available ich treatment, Tetra ContraSpot. Treatment is one dose every 5 days. Performed first dose. Because he didn't have a heater, we bought an 8 gallon tank 4 days later (moving him to the new tank on the day of his 2nd treatment bc a full water change is recommended on the bottle). New tank has pleco and plants, plenty of space, good environment. We have been unable to obtain a water testing kit, so I cannot tell you the PH or Nitrate/Nitrate levels.
In the new tank he received his second of 3 minimum doses of ContraSpot and the tank has been at a constant 86 degrees for 7 days in order to fight the ich. We moved the temp up slowly over the course of a whole day to prevent shock. Betta had been slightly lethargic but eating and not showing any severe signs of stress/disease. For about 5 days now he's been laying on the top of the filter just below the water line in the tank. Yesterday was the first time that he showed no visible signs of ich.
Today is the 12th day in the new tank and just yesterday the betta became bloated. On the 11th day (day after 3rd dose/water change), he is ich-free but clearly sick. He will not move. Believed that he might be constipated, so we did not feed him and were planning on trying the peas. This morning, however, everything is severe. His bloating is excessive, he is not moving unless he absolutely has too, he is losing color on his face and belly and he is pooping white/yellow clumps that are still not releasing from his body.
I wish that I could go to a store and ask questions, but between the language barrier and the lack of supplies I am a little stumped as to how to proceed. The only other medication that was available for freshwater fish besides the ContraSpot was a fungus treatment, also by Tetra.
Here is the form:

Housing
What size is your tank? 8 gallon
What temperature is your tank? 86 degrees/11 days
Does your tank have a filter? Yes, carbon removed for meds
Does your tank have an air stone or other type of aeration? Yes
Is your tank heated? Yes
What tank mates does your betta fish live with? One pleco

Food
What type of food do you feed your betta fish? Dried brine shrimp/1/2 of one/day
How often do you feed your betta fish? Once a day in the morning
Maintenance
How often do you perform a water change? Because of ich treatment every 5 days
What percentage of the water do you change when you perform a water change? 100 %
What type of additives do you add to the water when you perform a water change?
With each water change the tank has been getting the ich treatment, AquaSafe (Tetra), mineral salt (tetra, 1/2 tsp), plant food

Water Parameters:
Have you tested your water? If so, what are the following parameters?No kits found yet
Ammonia:
Nitrite:
Nitrate:
pH:
Hardness:
Alkalinity:

Symptoms and Treatment
How has your betta fish's appearance changed? He has grayed
How has your betta fish's behavior changed? He is just laying near the surface
When did you start noticing the symptoms? 5 days ago, 2 days severe
Have you started treating your fish? If so, how? 11 days ago
Does your fish have any history of being ill? He is still being treated for ich
How old is your fish (approximately)? No idea, seemed to be a juvenile when we bought him.

Please help. I am doing everything in my power to save this fish and with only the Internet to guide me I am having some difficulty figuring out how to proceed because I cannot identify what is wrong. The only camera we have here takes terribly blurry pictures but I will try to get pics up as soon as I can.

Sorry he's not doing well. Stop the meds, the only thing needed if it is ich is heat, good vacuuming & water changes, it is possible the meds are causing his issue. It can 2-3 wks to get rid of ich, you'll want to leave the temp up for at least a week after the last spot is seen. Also, an 8g is way too small for a pleco so you will want to rehome him or get a much larger tank. I see you are doing 100% water changes every 5 days because of the meds, but you will want to do about 50% or so water change every other day to keep the ammonia & such at acceptable levels until the tank has completed cycling. Unfortunately, unless you can get the water tested you will not know for certain when it finishes but it can tak 6-8 wks.

Do you have access to any Epsom salt (magnesium sulfate) any Oak leaves or Indian almond leaves in that area.

Can you tell if his scales are sticking up or is he just bloated.

I would get him in a small container that can be floated in a heated tank to maintain a temp of about 76-77F for treatment. Cover the top of the Qt with something-I use plastic veggie wrap-to retain the heat/humidity over the water for the labyrinth organ.

Premix some treatment water in a 1gal jug of dechlorinated water-Add Epsom salt 3tsp/gal and a tannin source if you have one-Either IAL (1lrg crushed/gal) or naturally dried and fallen from the tree-Oak leaf (20crushed/gal)-If you added a tannin source-Let the water steep for 30min to start the tannins releasing and salt to dissolve-Shake well before use.

Using this premixed treatment water-make 25% water changes every 15min for 1 hour today.He needs to stay in the small covered QT in this treatment water for the duration of the treatment period of 14 days.

Tomorrow-using the premixed treatment water-make 50% daily water changes.If you used a tannin source-the water should look darker every day in the 1gal premixed jug. Don't worry about any leaf bits that fall in the small QT with the Betta.

Nutrition-if you have access to any live mosquito larva-offer several rinsed several times a day and a good quality varied diet fed in small frequent meals.

Thank you both for your help, but unfortunately my fish died during the night. Now we'll deal with finding a testing kit somewhere. The pleco will be moved to a friend's 150 tank when he outgrows ours. That guy doesn't have a testing kit either! Thank you again.